@vaughnbros I prefer Ouphe over null rod since FoV is a thing and you need beaters as the deck is devoid of much besides control and lock. Chalice is a good add. Demonic grabs Maralen or Agent or Ramunap or Strip, which is great, since the deck really hinges on a couple key strategies (mana lock or search lock). Symmetry is also additional tutors for those few cards and is great combo with field/surgical (they HAVE to shuffle). Symmetry + agent is also backbreaking: get a card you want topdeck and grab their ancestral or anything? Could go to 2 Symmetry, cut 2x liliana, and add some more fast mana/3rd ouphe/Chalice. Similarly, you could go to 2 Maralen and keep symmetry to grab her. Having turn 1 flashed agent into turn 2 Maralen is awesome. I really want a Mana Crypt to facilitate turn 1 Agent more, but without tinker or any way to sac it, I think it kills yourself 9/10. Also nonbo with ouphe.
Karn/Lattice is a safe include for this list I think. If you have rituals I would consider other toolbox artifact options for the SB for karn to grab like Tormods crypt or something.
I would not cut DT, it is way too strong. Maralen is probably not needed so much as it can lock up a match so I would think go down to 2 of thoes.